Electric discharge device



June 14, 1932.

F.R.BECKERT Filed Dec.

ELECTRIC DI SCHARGE DEVICE Inventor Frank R. Beckert,

BWwZZaM H'Ls Attorney.

Patented June 14, 1932 UNITED STATES PATENT OFFICE FRANK R. BECKERT, OFSCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK ELECTRIC DISCHARGE nnvrcn Application filedDecember 27, 1928. Serial No. 328,739.

My invention relates to electric discharge devices such as mercury arcrectifiers for example, and has for its principal object the provisionof an improved resilient and con- 6 ductive lead-in conductor for suchdevices.

In mercury arc rectifiers, it issometimes desirable to use grid orcontrol electrodes for controlling the current flow from each anode andfor protecting the anodes from arc-back during the negative half cycleof the potential applied to the rectifier. The control electrodes are ofvarious forms but must be insulated in each instance from the conductivewalls of the rectifier, and must be mounted near the end of the anodes.The anodes are mounted within sleeves to protect them from mercuryparticles emitted from the cathode, and the control electrodes aretherefore, also mounted within the sleeves. Because of this mounting theelectrodes are inaccessible and it is difficult to attach to them alead-in conductor which must necessarily be attached after the electrodeis mounted within the anode sleeve. The lead-in conductor projectsthrough and is insulatingly sealed to the wall of the rectifier by meansof a vitreous material such as glass.

It has been customary to thread the leadin conductor into a tapped holein the wall of the electrode. This method has the disadvantage that itis difficult to thread the con ductor into this hole and due to theunequal expansion of the walls of the rectifier and the lead-inconductor, the conductor seals were quite often broken.

In accordance with my invention these difficulties are overcome byproviding a resilient and conductive member supported by the grid orcontrol electrode and arranged to engage the lead-in conductor.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawing and itsscope will be pointed out in the appended claims.

Referrln to the drawing, Fig. 1 illustrates a section of a mercury arcrectifier illustrating one of the anodes, control electrodes and thelead-in conductor attached to the latter in accordance with myinvention. Figs. 2 and 3 illustrate details of the lead-in conductor andits connection to the electrodes and Fig. 4 illustrates a modificationof my invention.

Fig. 1 illustrates a section of a rectifier casing 10, a sleeve 11attached thereto and forun 1ng a recess for'the anode 12. A sleeve 13pro ecting into the tank 10 is mounted at the lower end of sleeve 11 andsupports funnel shaped bafile or nozzle 14 which directs the rectifyingarc toward the tip of the anode 12. A control electrode 15 comprising ametallic sleeve 16 having a wire screen 17 across its end is supportedby an insulator 18 within the sleeve 11 directly below the anode 12. i

A lead-in conductor 19 surrounded by an insulating sleeve 20 projectsthrough a metall1c sleeve 21 attached to and projecting through the wallof cylinder 11 and a casing 22. The casing 22 surrounds tank 10 andforms a water jacket about the tank through which cooling water iscirculated during the operation of the rectifier.

The lead-in conductor 19 terminates in a member 23 which is sealed bymeans of a glass seal 24 to a member 25. The member 25 is in turnattached to the sleeve 21 by means of a member 26. The aluminum wiregasket 27 provides a vacuum tight joint between these two members.

It is evident that the electrode 15 is quite inaccessible and. that itis difiicult'to obtain a good conductive connection between it and thelead-in conductor. I have therefore in accordance with my inventionprovided a cup shaped member 28 which is attached to the electrode 15and supports a coil spring 29. The spring 29 is a. helical coil ofsufficient length and diameter so that when it is coiled within the cup28 the circle formed by the inner extremities of its turns is slightlysmaller than the diameter of the lead-in conductor 19. The member 28 iswelded or otherwise attached to the control electrode 15 and its wallsare turned in after spring 29 is 9 placed therein so that the latter isheld in place within the cup.

When assembling the rectifier the electrode 15 is placed so that member28 will line up with sleeve 21 with only a fair degree of accurac Thelead 19 is then simply inserted into t e sleeve 21 and ushed down untilits lower end is gripped y the resilient turns of the spring 29. Theresiliency of the spring and the diameter of the turns thereof provideor within the rectifier tank, and to complete the seal after it has beenso mounted. For

such instances I have modified my invention as illustrated in Fig. 4.The resilient connection in this construction is made between theterminal member 30 and the lead 31. Lead 31 is a straight conductorthreaded into the electrode sleeve 16 and extending back into the member30. Member 30 corresponds to a combination of the members 23 and 28 ofFig. 1 and the spring 29 is held therein as in part 28.

The conductor 31 is made long enough so that it extends past the spring29 and may freely expand or contract without interfering with itscontact between the spring and itself and without injury to the glassseal 24. V

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. An electric discharge device provided with an electrode mountedwithin an evacuated vessel, a sleeve connected to a wall of said vesseland projectin outwardly thereof, a terminal supported by and insulatedfrom saidsleeve, a connection including a rigid member and a helicalspring interposed between said electrode and said terminal, said sleeveenclosing a portion of said rigid memher, and a cup-shaped membermounted upon said electrode for supporting said spring.

2. An electric discharge device provided spring closely adjacent saidelectrode and in electrical connection therewith, and means including atubular member connected to said vessel and enclosin a portion of saidrigid member to guide said rigid member into engagement with saidspring.

In witness whereof, I have hereunto set my hand this 26th da ofDecember, 1928.

I RANK R. BECKERT.

with an electrode mounted within an evacu- Y ated vessel, a terminalinsulated from said vessel, a connection including a resilient memberand a rigid member adapted slidably to engage said resilient member,said connection being interposed between said electrode and saidterminal, means to mount said resilient member upon said electrode, andmeans including a sleeve connected to said vessel and enclosing aportion of said rigid member to guide said rigid member into engagementwith said resilient member.

3. An electric discharge device provided with an electrode mountedwithin an evacuated vessel, a terminal insulated from said vessel, aconnection including a helical spring and a rigid member adaptedslidably to engage said helical spring, said connection being interposedbetween said electrode and said terminal, means to mount said helical

